Electrical connecter



NOV- 12, 1929. I .1.w. HAMILTON 1,735,316

ELECTRI GAL CONNECTER Filed June 21, 192'? 9 7 /3 /2 /9 INVENTOR A TTORNEYS Patented Nov. 12, 1929 UNITED STATES PATENT OFFICE ELECTRICAL CONNECTER Application yfiled June 21,

This invention relates to improvements in electrical connecters, and has particular reference to a connecter of the separable type such as used in making connections for lamps,

5 heaters, irons and other electrical appliances.

In one type of separable connecter almost universally used, the plug member is provided with two prong terminals which are insertable into corresponding openings formed in the socket member in order to establish an electrical circuit through the connecter. It is well known that difficulties are experienced particularly in certain circumstances, in joining the members of the connecter, such as the inconvenience of aligning the terminals with the openings when joining the members and the fact that with the members already joined the socket member cannot subsequently be threaded into a receiving socket without twisting the conductors connected to the plug member.

An object of the present invention is to overcome the above difiiculties by providing a separable connecter of simple, practical and inexpensive construction, wherein an electrical connection between two conductors is effected with a plug member having only one terminal which is insertable into a single opening in a socket member from any position of rotation of the plug member relative to its longitudinal axis, and wherein the socket member, after its connection with the plug member, may be rotated with respect thereto for threading into a terminal socket without affecting the electrical connection established by the joining of said members.

Another object is to provide a separable connecter in which the plug terminal of one of the members thereof is formed from a single piece of resilient material bent into substantially cylindrical form and provided with a contact which will make positive andyielding connection with a socket terminal when the members of the connecter are oined together.

A further object is to establish a positive connection between the sleeve contact of the socket member and a contact element of the plug member, irrespective of the relative po-v sitions of rotation of said members with re- 1927. serial No. 200,320.

spect to each other, by providing said socket member with an annular contact permanently connected to said sleeve contact and adapted to project into said plug'member and continuously engage said contact element thereof.

A further object is to provide a separable connecter of improved construction wherein an 'electrical connection is established therethrough when the single plug terminal of the connecter is projected through the socket member and brought into direct engagement with a contact of a wall socket into which the socket member is capable of being inserted.

The above and other objects will appear more clearly from the following detail description, when taken in connection with the accompanying drawing, which illustrates a preferred embodiment of the inventive idea.

In the drawing- Figure 1 is an elevation of the plug and socket members constituting the connecter of the present invention;

Figure 2 is an enlarged vertical longitudinal section through the members in their connected position;

Figure 3 is a side elevation of the members connected, partly broken away and shown in section;

l Figure 4 is an end elevation of the socket member; and

Figure 5 is a section on the line 5-5 of I Figure 3, showing the plug member in end elevation.

The body portions of the plug and socket members 6 and 7 are made of any suitable insulating material, such as is usually employed in connecters of this type. The plug member 6 is provided with an opening 8 extending therethrough which is tapered to receive the inner end of the substantially cylindrical plug terminal 9, also preferably tapered throughout its entire length, with the outer reduced end of said terminal adapted for insertion into a tapered o ening 10 eX- tending through the socket mem er 7.

The plug terminal 9 is preferably formed lfrom a single sheet of conducting and resilient material which is bent into its ltapered and cylindrical form with the longitudinal y spring contact.

edges of the sheet spaced from each other, as indicated at 11 in Figure 5, so as to permit of a slight contraction of the diameter of the terminal when inserting the same into the opening 8 and also allow for the expansion of said terminal, due to the resiliency of the material, so that it will engage snugly with the wall of said opening. At the free eXtremity of the projecting portion of the terminal the material thereof is rolled to provide an annular bead 12 which, when said projecting portion is inserted into the opening 1() of the socket member, will engage in an annular groove 13 formed in the latter member to thus aid in frictionally retaining the plug and socket members in connected position. To further secure the terminal 9 in the member 6 a screw terminal 14 is threaded through said plug terminal and into a block of conducting material 15 embedded in the body of the member 6, said screw also acting to secure the conductor 16 of an electrical circuit in electrical contact with the plug terminal, the other conductor 17 of said circuit being connected in a manner which will presently appear. From a point intermediate the ends of the projecting portion of the plug terminal 9 to the inner end thereof the material is cut to form a longitudinally extending strip or tongue 18 which is subsequently bent into substantially S formation, as shown in Figure 2, with the portion of said strip adjacent its free end projecting beyond the outer eX- tremity of the plug terminal and the adjacent end of the socket member 7 to form a tip contact 19, said portion preferably having frictional engagement with the inner wall of the plug terminal. This tip contact 19 1s adapted to engage a contact in the usual wall socket terminal employed with connecters of this type and thereby forms a conducting medium for the connection of the conductor 16 with one terminal of a source of electrical current. At the inner extremity of the pro- A jecting portion of the plug member 9 the longitudinal slot formed by the cutting of the strip 18 and consequent bending thereof 1s enlarged, as indicated at'20 (Figures 1 and 5), to aiford suiiicient space for the insertion of a screw driver or other implement so that it ymay be engaged with the screw 14 when securing the plug terminal 9 and the conductor 16 in position.

The inner face of the plug member 6, which Y comes adjacent to the socket member 7 when the two members are connected, is provided therein with an annular recess 21 in which `there is secured a spring Contact 22 by means of a screw 23 which is also utilized to connect the extremity of the conductor 17 to said The contact 22 is curved longitudinally to conform to the contour of the recess 21 and is also bent so as to project outwardly toward the face of the plug member to thereby engage the edge of the projecting portion of an annular or ring contact 24 embedded in the socket member 7. By the provision of this annular contact it will be apparent that some portion thereof will always engage the Contact 22 regardless of the position of rotation of the socket member 7 about its longitudinal axis when said ring contact is inserted into the recess 21 at the time of establishing the connection between the members 6 and 7. Likewise,by the provision of the cylindrical plug terminal 9 and its position of rotation relative to the socket member 7, this engagement of the contacts 22 and 24 will also be effected when the two members 6 and 7 are being joined. The inner edge of the contact 24 which is embedded in the member 7 is formed with two opposed projecting portions or flanges 25 which eX- tend to a point adjacent the inner ends of two recesses 26 formed in the outer wall of the socket member 7 and said portions are engaged by the inner extremities of the two inturned tongues 27 formed upon'one end of the sleeve Contact 28 which encircles said socket member. This contact 28 is of the usual screw threaded type which permits of the socket` member being threaded into the usual socket terminal previously mentioned. The sleeve contact 28 and its tongues 27 may be secured in position with said tongues in permanent engagement with the portions25 of the ring contact 24 by means of solder 29 placed in the recesses 26 or the portions 25 and 27 may be riveted together and the unit formed thereby placed in the mold when forming the .socket member 7. From this construction it will be obvious that the conductor 17 is electrically connected to the sleeve contact 28 through the intermediary of the contacts 22 and 24.

Thus, not only can the two members 6 and 7 be joined and an electrical connection established regardless of the position of rotation ot either member relative to the other, but it will also be apparent from the foregoing description that, contrary to the usual type of plug employed, the two members 6 and 7 may first be joined and the member 7 thereafter threaded into a socket terminal by rotating the same relative to the member 6. To do this, the latter member need only be held against rotation with one hand while the member 7 is threaded into its socket with the other hand, and as a result the conductors 16 and 17 will not be twisted, as would occur in attempting to accomplish the operation with the usual type of connecter wherein the plug and socket members cannot be rotated relative to each other after being connected.

It is also to be noted that when the member 7 is screwed into a wall socket no electrical connection with the usual center contact of the latter will he established until the plu terminal 9 has been completely projected ,with said contact.

through the member 7 to engage its tip 19 Due to this arrangement the plug terminal may be partially inserted into the socket member and left in this position without closing the ,circuit through the two conductors 16 and 17, whereby the connecter is in readiness for immediate use by simply moving the plug terminal a slight distance inwardly to complete its projection through said socket member and into engagement with the center contact, of the wall socket. Likewise, the electrical connection may be broken by only a partial extraction of the plug terminal from the socket member and in this position the plug member will be supported by the socket member.

What is claimed is:

1. A separable electrical connecter, including a plug member, a single plug terminal eX- tending therefrom and to which one conductor is connected, said plug terminal being tapered and of substantialy cylindrical formation and having a projecting portion provided adjacent its inner end with an annular bead, a contact carried by said plug member or connection to another conductor, a socket member having an opening for receiving said plug terminal and having an annular groove in which said bead is engageable when the plug terminal is inserted into said opening,

- andV a contact carried by said socket member tending therefrom,

for engagement with the irst named c ontact irrespective of any position of rotation of either of said members relative .to the other f about their longitudinal axes.

2. A separable electrical connecter, including a plug member, a single plug terminal eX- tending therefrom, said plug terminal being formed from a sheet of resilient material bent into substantially cylindrical form with one end of the plug terminal mounted in said plug member and its other end projecting therefrom, the material of said plug terminal being cut to provide a strip having its free extremity extending outwardly from the projecting end of said plug terminal for engagement with an electrical contact, a contact carried by said plug member, a socket member having an opening for receiving said plug terminal. and a Contact carried by said socket member for0 engagement with the contact carried by said plug member.

3. A separable electrical connecter, including a plug member, a single plug terminal eX- said plug terminal being formed from a sheet of resilient material bent into substantially cylindrical form with one end of the plug terminal 'mounted in said plug member and its other end projecting therefrom, the' material of said plug terminal being cut to provide a strip having its free extremity extending outwardly from the projecting end of said plug terminal for engagement with an electrical contact, a contact carried by said plug member, a socket member having an opening for receiving said plug terminal, and an annular contact carried by said socket member and encircling the open-' ing therein, said annular contact having a projecting portion engageable with the contact carried by said plug member when said ,plug and socket members are `joined in any position of rotation of either member relative to the other.

,4. 1 A separable electrical connecter, including a plug member, a single plug terminal extending therefrom, said plug terminal being formed from a sheet of resilient material bent into substantially cylindrical form with one end of the plug terminal mounted in said plug member and its other end projecting therefrom, the material of said plug terminal being cut to provide a strip having its free extremity extending outwardly fromthe proj ecting end of said plug terminal for engagement with an electrical contact, a contact carried by said plug member, a socket member having an opening for receiving said plug terminal', an annular contact carried by said socket member and encircling the opening therein, said annular contact having a projecting portion engageable with thecontact asv carried by said plug member when said plug completely through said opening to engage a contact of a wall socket, and contacts lfor completing an electrical circuit in any position of rotation of said socket member relative to said lu terminal when the latter is engaged wit t e first named contact.

6. A separable electrical connecter including a socket member having an opening therethrough, a plug member, a single terminal carried by said plug member and projectable through saidl opening to engage a contact of a wall socket, and contacts carried by said socket and plug members for completlng an electrical circuit in any position of rotation of either of said members relative to `the other about its longitudinal axis when said terminal is engaged with the first named cntact. l

7 A separable electrical connecter including a socket member having an opening therethrough, a plug member havin a contact, a single plug terminal adapted or projection throng said opening to engage the same` with a contact of a wall socket, and a contact carried by said socket member for engagement with the first named contact when said plug terminal is projected through'said openmg.

8. A separable electrical' connecter including a socket member having an opening therethrough, a plug member havin a contact, a single plug terminal adapted or projection through said opening to engage the same with a contact of a Wall socket, and an annular .contact partially recessed Within said socket member and engageable with the first named Contact when said plug terminal is projected through said opening.

9. A separable electrical connecter including a socket member having an opening therethrough and also provided With-only'a single cntact for engagement with a contact of a Wall socket, a plug member, a plug terminal carried thereby insertable into theopening in said socket member to support said plug member Without establishing electrical connection With said Wall socket, said plug terminal being projectable through said opening to engage another contact of said wall socket, andA other contacts carried by said socket and plug members for completing an electrical connection when said plug terminal is engaged With its associated Wall socket contact.

l0. A separable electrical connecter including a socket member having an opening therethrough and also provided With only a single vContact for engagement with a contact of a wall socket, a plug terminal for projection ythrough said opening to engage another contact of said Wall socket, and other contacts ordcompleting an electrical connection when sai jecte through said opening.

In testimony whereof I have aixed my signature. JOE WHEELER HAMILTON.

(plug terminal has been completely pro- 

